Three factors in the biology of juvenile sockeye salmon of the 

 Naknek system are of special significance to the managers of the 

 resource and should be investigated in any effort to enhance the 

 production of sockeye salmon in the Naknek system: (U the 

 abundance of smolls each spring is fairly constant for the system as 

 a whole and not closely related to the abundance of the parents or, 

 from 1961 M. even to the original abundance of age fish; (2) the 

 apparent growth of juvenile sockeye salmon and potential 

 competitor species is not related to the abundance of these fish in 

 any lake of the Naknek system; and 13) two major lakes, 

 constituting about 35% of the rearing waters, do not receive age 

 sockeye salmon from other basins and are supporting relatively few 

 sockeye salmon. 



Ttie question of what escapement of adult .sockeye .salmon is 

 needed to ensure full production of juveniles is considered. The 

 present study indicates that escapements in the range of 600.000 to 

 1.000.000 fish, as recommended by other studies, would probably 

 fully use the present combination of spawning and rearing areas 

 without danger of overburdening the food supply. 



679. Kinds and Abundance of Zooplankton Collected by the 

 USCG Icebreaker Glacier in the Eastern Chukchi Sea, 

 September-October 1970. By Bruce L. Wing. August 

 1974, iv + 18 p., 14 figs., 6 tables. 



ABSTRACT 



Zooplankton samples were taken at 39 oceanographic stations in 

 the eastern Chukchi Sea in September and October 1970. Sampling 

 was done by vertical tows from near bottom to the surface with a 

 0.5 m diameter No. (0.57 mm) mesh NorPac standard plankton 

 net. Data are presented on the distribution and relative abundance 

 of 63 categories of zooplankton at the onset of winter. Zooplankton 

 abundance generally was lowest in waters with temperatures below 

 0°C; it did not appear to be associated with the distribution of 

 salinity; and it tencJed to be inversely related to dissolved oxygen 

 concentration. Comparison of zooplankton abundance in 1970 with 

 published observations on the Chukchi Sea in 1947 shows probable 

 .seasonal variation of meroplankton abundance and yearly variation 

 of holoplankton abundance. 



680. Pelagic Amphipod Crustaceans from the Southeastern 

 Bering Sea, June 1971. By Gerald A. Sanger. July 1974, 

 iii + 8 p., 3 figs., 3 tables. 



ABSTRACT 



Fourteen species of pelagic amphipods were present in zoo 

 plankton samples collected from the southeastern Bering Sea in 

 June 1971. Parathemisto pacifica strongly dominated relative 

 abundance (68 96%) and was present in numbers up to an estimated 

 2,755/1,000 m' of water. Primno macropa, was the only other 

 species present m all hauls and ranged from 4 to 27% in relative 

 abundance. Cyphocans challengeri was present in numbers up to 

 48/1.000 m^ during night hauls, but only one animal was taken in 

 all daylight hauls. Hyperia medusarum was pre.sent in 14 (82%) of 

 the hauls but accounted for less than 1% of the total numbers. 



A presumed diurnal vertical migration was evidenced for 

 Primno macropa, Cyphocaris ckallengeri, and possibly for Scina 

 rattrayi Hyperuche medusarum, and Hyperia medusarum. 



The occurrence of Sci7m s(e66myi, S. rattrayi, Vibilia caeca {'?), 

 Paraphronima crassipes, Phronima sedentaria, and Primno 

 macropa extended their known ranges in the Bering Sea eastward, 

 and the occurrence of Cyphocaris anonyx represents a new record 

 for the Bering Sea. 



681. Physiological Response of the Cunner. Tautogolabrus 

 adspersus, to Cadmium. October 1974, iv + 33 p. 



SUMMARY ABSTRACT 



The cunner, Tautogolabrus adspersus, was exposed to six 

 concentrations of cadmium, as cadmium chloride (CdCh • 2'/!H2 0'. 

 for 96 h. At the end of this exposure period, tests of blood serum 

 osmolality and gill tissue oxygen consumption were performed. 

 High levels (48 ppm) of this metal resulted in abnormallv high serum 

 osmolality, ana an exposure as low as 3 ppm reduced the normal 

 rate of oxygen consumption. Both of these parameters may be 

 related to observed tissue damage. 



The hislopathological effects of acute exposure of the cunner to 

 cadmium were manifested in the kidney, intestine, hemopoietic 



tissue, epidermis, and gill. Few significant changes were noted in 

 fish exposed to concentrations less than 48 ppm. The results 

 implicate renal failure as the probable cause of death subsequent to 

 acute exposure to cadmium. 



Clearance of intracardially injected bacteria from the blood of 

 cunners exposed to 12 ppm cadmium was examined. The rate of 

 bacterial uptake in the cells of the liver and spleen was increased, 

 but the bacterial death rate within these cells was decreased. 

 Exposure of fish at 3 to 24 ppm failed to influence antibody 

 production against sheep red blood cells. 



The activity of two liver enzymes changed significantly with 

 exposure to cadmium. Aspartate aminotransferase was lower in the 

 exposed fish, and a magnesium linked oxidoreductase in exposed 

 fisn required 10 times as much added magnesium to reach the same 

 level of activity as in the control fish. 



Chemical analyses were made for uptake and clearance of 

 cadmium from exposed cunners. In the uptake study, cadmium 

 residues averaged 8.5 times higher in liver than in gills. In the 

 clearance study, substantial reductions in cadmium residues were 

 found in the gills and blood of fish held in clean seawater for 6 wk 

 after exposure to cadmium, as compared to fish sacrificed 

 immediately after exposure. Mu.scle and carcass samples from the 

 "cleared" fish showed little reductions in cadmium levels. 



(681.) Physiological Response of the Cunner, Tautogolabrus 

 adspersus, to Cadmium. I. Introduction and Experimental 

 Design. By Anthony Calabrese, Ries S. Collier, and James 

 E. Miller. October 1974, p. 1-3. 



(No abstract) 



1681.) Physiological Response of the Cunner, Tautogolab- 

 rus adspersus, to Cadmium. II. Uptake of Cadmium by 

 Organs and Tissues. By Richard A. Greig, Albert E. 

 Adams, and Betty A. Nelson. October 1974, p. 5-9, 2 figs., 

 2 tables. 



ABSTRACT 



Cadmium uptake and clearance data were obtained on cunners, 

 Tautogolabrus adspersus, exposed to various concentrations of this 

 metal in artificial seawater. 



In the uptake study, cunners were exposed to 0, 3, 6. 12, 24, and 

 48 ppm cadmium in seawater for 4 days. Cadmium residues 

 averaged 8.2 times higher in livers than in gills. At the 48 ppm 

 cadmium expo.sure level, the livers averaged 195 ppm, as compared 

 to 33.5 ppm for gills (wet weight values). 



In the clearance study, cunners were exposed to 24 ppm 

 cadmium in seawater for 4 days, after which time half of the fish 

 were placed in clean flowing seawater for 1 mo and half were 

 sacrificed immediately to determine initial cadmium residue 

 concentrations. Gill, liver, blood, muscle, and carcass samples were 

 analyzed. Substantial reductions in cadmium residues were found in 

 the gills and blood of fish held in clean seawater. as compared to 

 samples from fish sacrificed immediately after exposure to 

 cadmium. Livtr samples produced variable results: livers of fish 

 held in clean seawater for 1 mo contained 62-155 ppm cadmium for 

 four fish and 5-11 ppm for three fish, as compared to 30-117 ppm for 

 livers from eight fish s.acrificed immediately after exposure to 

 cadmium. Muscle and carcass samples from the "cleared" fish 

 showed very little reduction in cadmium levels. 



(681.) Physiological Response of the Cunner, Tautogolabrus 

 adspersus, to Cadmium. III. Changes in Osmoregulation 

 and Oxygen Consumption. By Frederick P. Thurberg and 

 Margaret A. Dawson. October 1974, p. 11-13, 1 fig. 



ABSTRACT 



The cunner, Tautogolabrus adspersus, was expo.sed to various 

 concentrations of cadmium, as cadmium chlori(ieiCdCl!-2'/2H20). 

 for % h. .'\t the end of this exposure period tes;..-; of blood serum 

 osmolalitv and gill tissue oxygen consumption were performed. 

 High levels 148 ppm) of this metal resulted in an abnormally high 

 serum osmolality and an exposure as low as 3 ppm reduced the 

 normal rate of oxygen consumption. Both of these parameters may 

 be related to observed tissue damage. 



(681.) Physiological Response of the Cunner, Tautogolabrus 



13 



